Disks used in hard drive media frequently include an aluminum-magnesium (AIMg) substrate that is plated with a material such as nickel-phosphorous (NiP) to provide a smooth surface on which to deposit magnetic recording layers upon which data may be stored. To accommodate the growing demand for increased data storage space, future hard disk drives may utilize technologies such as EAMR (Energy Assisted Magnetic Recording), which require magnetic recording layers with high magnetic anisotropy (Ku). Such magnetic recording layers may include alloys that require deposition temperatures in excess of 300° C. The Ni—P coating currently used to provide smooth surfaces on which to deposit the magnetic recording layer, however, cannot withstand temperatures this hot, without dramatically increasing in surface roughness.